Transmitter for telephony



Jan. 13, 1931. H. KUCHENMEISTER TRANSMITTER FOR TELEPHONY Filed 00t- 1926 Patented Jan. 13, 1931 UNITED STATES PATENT OFFICE HEINRICH' KuoHENMEIs'rER, or IBERLI-N, GERMANY TRANSMITTER ron TELEPHONY Application filed October 4, 1926, Serial No.

, It is known to increase-the volumefof;

' sound in talking machines by arranging microphones one in back of the other whereby the same sound is reproduced within certain time intervals. 7

The object of this invention is an arrangement of. apparatus which permits this idea to be applied to telephone transmitters.

The drawing illustrates diagrammatically 10 one form of the invention.

In the present instance, four transmitter microphones 1 to 4; having individual diaphragms are arranged before the person 1 using the telephone in succession to oneanother, preferably as the accompanying drawing shows, in a single trumpet 5 say 80 cms. long. The microphones 1 and 4 are 9 arranged at opposite ends of the trumpet while the microphones 2-and 3 are disposed '2 at intermediate points therein. It is advantageous to adjust the sensitivity, that is 139,338, and in Germany October 13, 1925.

V HEINRICH KUCHENMEISTER.

widely apart the transmitting strength of the individual I microphones in such a way that the resulting" impulses are equally strong in spite of the varying distances of the microphones from the source of sound, for example the mouth.'

The time intervals of less than one hundredth of a second resulting from the separation is sufiicient to produce that multiple overlapping of the sound impulses which is received by theiearlas an enhanced fulness o of the tones. It is thus possible to obtain good reception in spite of unfavourable, conditions particularly in long distance telephone lines. p o i The reception can be notably improved by using two transmission lines instead of one, the second line being led to a second receiver. Thus, when a series of four m1- crophones are employed, as herein shown,

two of them, for instance the microphones 1 and 3, are connected to one transmission line 6 and the microphones 2 and 4 are' joined to the line 7 and each line is provided with an individual receiver, conventionally shown at 8. I c What I claim is i- 1. In a telephone transmitter, a a single trumpet and groups of microphones supported within said trumpet in aligned rela-. 

